Nano-structure and method of fabricating nano-structures
In one embodiment, a method for fabricating a nano-structure includes forming a feature on a substrate, depositing multiple layers of material over the substrate and feature to form a multi-layer stack, depositing a film over the multi-layer stack, removing a portion of the film and the multi-layer stack to expose edges of the layers of material, and removing portions of the layers of material to form trenches at a surface of the nano-structure.
This application is a continuation-in-part of copending U.S. utility application entitled, “Fabrication and Use of Superlattice,” having Ser. No. 10/817,729, filed Apr. 2, 2004, which is entirely incorporated herein by reference.
BACKGROUNDAlthough fabrication of structures on a “nano” scale has been practiced for several years, there are still many challenges that are to be overcome to enable manufacture of desired structures.
For instance, problems can be encountered when a nano-structure is formed that includes a plurality layers of material that are to be planarized. Such problems may include, for example, fraying, delamination, erosion, dishing, and rounding.
Desired is a method for forming nano-structures that overcome or reduce such problems.
SUMMARYIn one embodiment, a nano-structure comprises a substrate, a feature formed on the substrate that extends upwardly from a surface of the substrate, layers of material that overlie the substrate surface and at least a portion of the feature, and an exposed surface comprising a top surface of the feature and edges of the layers of material, wherein portions of selected layers of material have been etched away to form trenches adjacent the top surface of the top surface of the feature.
In one embodiment, a method for fabricating a nano-structure comprises forming a feature on a substrate, depositing multiple layers of material over the substrate and feature to form a multi-layer stack, depositing a film over the multi-layer stack, removing a portion of the film and the multi-layer stack to expose edges of the layers of material, and removing portions of the layers of material to form trenches at a surface of the nano-structure.
BRIEF DESCRIPTION OF THE DRAWINGSThe disclosed nano-structure and method can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale.
Disclosed is a nano-structure and a method for fabricating nano-structures. According to at least one embodiment of the method, multiple layers of material that overlie a feature that is formed on the surface of a substrate are covered by a sacrificial film that enables planarization of the multiple layers while reducing or preventing one or more of fraying, delamination, erosion, dishing, and rounding.
Referring now in more detail to the drawings, in which like numerals indicate corresponding parts throughout the several views,
In this embodiment, the bump 106 has a trapezoidal cross-section that is defined by a base 108, opposed sides 110, and a top 112. As is apparent from
As is described above, the nano-structure 100 is constructed on a nano-scale. By way of example, the bump 106 has a height dimension, h, that ranges from approximately 200 nanometers (nm) to approximately 5000 nm, and a width dimension, w, that ranges from approximately 250 nm to 100 microns (μm). In one embodiment, the bump 106 has a height of approximately 2500 nm and a width of approximately 5000 nm.
It is noted that, although the feature has been illustrated and described as a bump, the feature could take substantially any other form including, for example, a step. Moreover, although specific example dimensions have been described, those dimensions are only examples, and the feature could have other dimensions, which may only be limited by the size of the substrate.
Referring next to
In the embodiment shown in the figures, nine layers 114 of material have been deposited. By way of example, each layer 114 is approximately 10 Angstoms (Å) to approximately 1000 Å thick. For instance, in one embodiment, each layer 114 can be approximately 500 Å thick.
With the structure illustrated in
To avoid such problems, a sacrificial or planarizing film 120 of material is deposited over the multiple layers 114 prior to planarization, as is shown in
At this point, the planarizing film 120 and the top of the multi-layered stack 116 can be removed. Specifically, as is indicated in
At this point, multiple trenches can be formed in the new surface 122, and the exposed edges of the stacked layers 114, that results from the planarization process. Referring to
The structure that results from the above-described fabrication is a comb-like structure in which diagonal or oblique trenches 124 are formed in the surface of the nano-structure 100. In particular, multiple parallel, oblique trenches 124 are formed on both sides of the bump 106 such that the trenches are angled toward each other as they are traversed upward from the bases 126 to the surface 122. By way of example, each trench 124 forms an angle, α, of approximately 30 to approximately 90 degrees relative to the surface 122 (see
An embodiment of a method for fabricating a nano-structure can be summarized as provided in
Referring next to block 804, a sacrificial film is deposited over the multi-layer stack such that the height of the film equals or exceeds the height of the multi-layer stack, including the portion of the stack that overlies the feature. Once the film has been deposited, a portion of the film and the stack is removed, as indicated in block 806, for example using a planarization process.
Finally, as is indicated in block 808, portions of various layers of the multi-layer stack are removed to form trenches in a surface that results when the portion of the film and stack are removed (in block 806). By way of example, the portions of the layers can be removed using a selective etching process.
Claims
1. A nano-structure, comprising:
- a substrate;
- a feature formed on the substrate that extends upwardly from a surface of the substrate;
- layers of material that overlie the substrate surface and at least a portion of the feature; and
- an exposed surface comprising a top surface of the feature and edges of the layers of material;
- wherein portions of selected layers of material have been etched away to form trenches adjacent the top surface of the top surface of the feature.
2. The nano-structure of claim 1, wherein the feature has a trapezoidal cross-section.
3. The nano-structure of claim 1, wherein the feature has a width adjacent the substrate surface of approximately 250 nanometers to approximately 100 microns.
4. The nano-structure of claim 1, wherein the layers of material comprise at least two different types of material.
5. The nano-structure of claim 4, wherein layers of different material are formed in an alternating arrangement.
6. The nano-structure of claim 5, wherein only the layers of one type of material have been etched away to form the trenches.
7. The nano-structure of claim 1, wherein each layer of material has a thickness of approximately 10 Angstroms to approximately 1000 Angstroms.
8. The nano-structure of claim 1, further comprising a planarization film adjacent the edges that overlies a portion of the layers of material.
9. The nano-structure of claim 8, wherein the planarization film is composed of silicon oxide.
10. The nano-structure of claim 1, wherein the trenches comprise opposed side walls and a base.
11. The nano-structure of claim 10, wherein the opposed side walls are formed from a first material and the base is formed of a second material.
12. The nano-structure of claim 1, wherein the trenches are oriented in an oblique direction relative to the exposed surface.
13. The nano-structure of claim 1, wherein the nano-structure is a nano-imprint stamp.
14. A method for fabricating a nano-structure, the method comprising:
- forming a feature on a substrate;
- depositing multiple layers of material over the substrate and feature to form a multi-layer stack;
- depositing a film over the multi-layer stack;
- removing a portion of the film and the multi-layer stack to expose edges of the layers of material; and
- removing portions of the layers of material to form trenches at a surface of the nano-structure.
15. The method of claim 14, wherein forming a feature comprises forming a dielectric bump on the substrate.
16. The method of claim 15, wherein the dielectric bump has a trapezoidal cross-section.
17. The method of claim 15, wherein the dielectric bump has a width adjacent a surface of the substrate of approximately 250 nanometers to approximately 100 microns.
18. The method of claim 14, wherein depositing multiple layers of material comprises depositing at least two different materials in an alternating arrangement such that the multi-layer stack comprises alternating layers of material.
19. The method of claim 14, wherein depositing a film comprises depositing a film over the multi-layer stack having a height that exceeds the top of the multi-layer stack.
20. The method of claim 19, wherein removing a portion of the film and the multi-layer stack comprises planarizing the film and the multi-layer stack together to form the surface of the nano-structure and the edges.
21. The method of claim 14, wherein removing portions of the layers comprises etching away portions of selected layers to form the trenches.
22. The method of claim 21, wherein etching away portions of selected layers comprises etching away layers of a first type of material without etching away layers of a second type of material.
23. The method of claim 21, wherein the method comprises a method for fabricating a nano-imprint stamp.
24. A method for fabricating a nano-structure, the method comprising:
- forming a dielectric bump on a surface of a substrate, the feature having opposed sides, at least one of the sides extending in an oblique direction from the substrate surface;
- depositing multiple layers of at least two different materials in an alternating manner over the substrate surface and the dielectric bump to form a multi-layer stack of alternating materials;
- depositing a film over the multi-layer stack such that the multi-layer stack is completely covered by the film;
- planarizing the film and the multi-layer stack to form a surface that comprises exposed edges of the layers of material; and
- etching away layers of one of the materials to form trenches in the formed surface, the trenches extending in an oblique direction relative to the formed surface.
25. The method of claim 24, wherein the dielectric bump has a trapezoidal cross-section.
26. The method of claim 24, wherein the dielectric bump has a width adjacent a surface of the substrate of approximately 250 nanometers to approximately 100 microns.
27. The method of claim 24, wherein the method comprises a method for fabricating a nano-imprint stamp.
Type: Application
Filed: Aug 31, 2005
Publication Date: Jan 5, 2006
Inventors: Sriram Ramamoorthi (Corvallis, OR), Peter Mardilovich (Corvallis, OR), Pavel Kornilovich (Corvallis, OR), Vincent Korthuis (Corvallis, OR)
Application Number: 11/215,985
International Classification: G03C 5/00 (20060101);